Update on resistance of Bacteroides fragilis group and related species with special attention to carbapenems 2006-2009.

The susceptibility trends for the species of the Bacteroides fragilis group against various antibiotics were determined using data from 4 years [2006-2009] on 1957 isolates referred by 8 medical centers participating in a National Survey for the Susceptibility of B. fragilis. The antibiotic test panel included doripenem, ertapenem, imipenem, meropenem, ampicillin:sulbactam, piperacillin:tazobactam, cefoxitin, clindamycin, moxifloxacin, tigecycline, chloramphenicol and metronidazole. MICs were determined using agar dilution methods following CLSI recommendations. Genetic analysis of isolates from 2008 with elevated MICs (>2 µg/mL) to one or more of the carbapenems to detect presence of the cfiA gene was performed using PCR methodology. The results showed an increase in the resistance rates to the ß-lactam antibiotics. High resistance rates were seen for clindamycin and moxifloxacin (as high as 60% for clindamycin and >80% for moxifloxacin), with relatively stable low resistance (5.4%) for tigecycline. For carbapenems, resistance in B. fragilis was 1.1%-2.5% in 2008-9. One isolate resistant to metronidazole (MIC 32 µg/mL) was observed as well as isolates with elevated MICs to chloramphenicol (16 µg/mL). Genetic analysis indicated that the cfiA gene was present in some but not all of the isolates with high MICs to the carbapenems. These data indicate that there continue to be changes in susceptibility over time, and that resistance can be seen among the carbapenems. High antibiotic resistance rates tend to be associated with specific species.

Clinical indications for probiotics: an overview.

Probiotic bacteria are used to treat or prevent a broad range of human diseases, conditions, and syndromes. In addition, there are areas of medical use that have been proposed for future probiotic applications. Randomized double-blind studies have provided evidence of probiotic effectiveness for the treatment and prevention of acute diarrhea and antibiotic-induced diarrhea, as well as for the prevention of cow milk-induced food allergy in infants and young children. Research studies have also provided evidence of effectiveness for the prevention of traveler's diarrhea, relapsing Clostridium difficile-induced colitis, and urinary tract infections. There are also studies indicating that probiotics may be useful for prevention of respiratory infections in children, dental caries, irritable bowel syndrome, and inflammatory bowel disease. Areas of future interest for the application of probiotics include colon and bladder cancers, diabetes, and rheumatoid arthritis. The probiotics with the greatest number of proven benefits are Lactobacillus rhamnosus strain GG and Saccharomyces boulardii.

Acute undifferentiated human diarrhea in the tropics. II. Alterations in intestinal fluid and electrolyte movements.

The nature and magnitude of fluid and electrolyte loss into the small intestine were defined by the marker perfusion technique in patients with acute undifferentiated diarrhea (AUD) in the tropics. The patients were divided into two groups according to their small bowel bacteriologic findings, namely those with a predominant Escherichia coli flora and those with a mixed flora. 11 normal subjects served as controls. Net jejunal fluid secretion occurred into the lumen in four of seven patients with E. coli flora and three of seven with a mixed flora. The magnitude of secretion in the jejunum was greater in the E. coli flora patients than in those with a mixed flora. Four E. coli patients and one mixed flora patient had net fluid secretion in the ileum, although the magnitude of secretion in this area was less than in the jejunum. Intestinal fluid had higher bicarbonate concentration in the ileum than in the jejunum but was isotonic in both regions. It resembled in composition fluid from the same region of intestine in normal individuals. Recovery of normal fluid and electrolyte absorptive function was usually complete in both jejunum and ileum by 6-8 days after onset of the disease. Increase in unidirectional flux rates for H(3)O and (24)Na occurred in acute E. coli flora diarrhea and returned to normal levels in recovery: increase in J(beta) (plasma to lumen flux) primarily accounted for the increase in fluid loss. Intestinal biopsy revealed no alterations in villous architecture.A relationship between small bowel fluid production and the presence of toxigenic strains of E. coli within the small bowel has been found for E. coli flora patients. In many respects this disease resembles acute cholera. The mixed flora group represents a less defined entity which requires further study.

Rapid diagnosis of anaerobic infections by direct gas-liquid chromatography of clinical speciments.

Current methods to isolate and identify anaerobic bacteria are laborious and time consuming. It was postulated that the short-chain fatty acids (SCFA) produced by these organisms might serve as microbial markers in clinical material. 98 specimens of pus or serous fluid were analyzed by gas-liquid chromatography, and findings were compared with culture results. Good correlations were found for the recovery of anaerobic Gram-negative bacilli and the presence of isobutyric, butyric, and succinic acids. 19 of 20 specimens with significant amounts of these acids (greater than 0.01 mumol/ml) yielded bacteroides or fusobacteria. Culture of the single "false-positive" specimen failed to grow anaerobic Gram-negative bacilli, although clinical data and Gram-stain suggested their presence. 77 of 78 specimens which has insignificant concentrations of the marker acids failed to yield anaerobic, Gram-negative bacilli in culture. The single "false-negative" specimen yielded Bacteroides pneumosintes, an organism which does not ferment carbohydrates. It is concluded that direct gas-liquid chromatographic analysis of clinical specimens provides a rapid presumptive test for the presence of anaerobic, Gram-negative bacilli.

Acute undifferentiated human diarrhea in the tropics. I. Alterations in intestinal micrflora.

The microflora of the small and large intestine was determined in 17 adults with acute undifferentiated diarrhea in Calcutta, India. On the basis of bacteriologic findings, the patients could be divided into two groups: those with a predominant flora of Escherichia coli (eight patients) and those with a mixed coliform flora (nine patients). In the former group, E. coli were distributed throughout the small and large bowel. Broth filtrates of these isolates contained an enterotoxin which caused fluid accumulation in the rabbit intestinal loop model. Toxigenic E. coli were cleared rapidly from the small bowel during the acute period; some patients only had the "hot" strains in their fecal effluent. During convalescence, the serotypes of E. coli changed and the new strains did not elaborate enterotoxin. Only one of the eight patients had a serotype previously associated with diarrhea. Acute undifferentiated diarrhea in the remaining cases was apparently caused by untypable E. coli or by typable strains not generally considered pathogenic. Small bowel and fecal cultures from the mixed flora group revealed a heterogeneous mixture of Gram-negative enteric bacilli and a distinct pattern could not be discerned. Further study will be needed to elucidate the cause of diarrhea in these cases.

Intestinal fluid and electrolyte transport in human cholera.

The site, nature, magnitude, and duration of fluid and electrolyte loss into the small intestine during the acute and recovery phase of human cholera was defined in 27 Indian patients. 11 subjects without cholera served as controls. The marker perfusion technique employed was shown, in preliminary experiments, to measure accurately jejunal and ileal fluid and electrolyte transmucosal transport rates under conditions of cholera diarrhea. Fluid loss into the lumen occurred from jejunal and ileal mucosa. The fluid was isotonic in both regions. Bicarbonate concentration was significantly higher in ileal than jejunal fluid during all phases of the disease. Bicarbonate concentration in both regions was significantly higher in acute cholera than during convalescence. Fluid loss into the intestinal lumen ranged from 0.07 to 10.9 ml/hr per cm. Losses were significantly greater from jejunum than ileum. Net ileal absorption was recorded in five of 10 acute cholera studies. During the acute phase of the disease, net jejunal fluid transport showed a positive correlation with fasting intestinal flow rate and stool output. Stool output was also positively correlated with jejunal fasting intestinal flow rates. Recovery of normal fluid and electrolyte absorptive function was usually complete in both jejunum and ileum by the sixth day after admission. These findings in human cholera validate the animal models of choleraic diarrhea and suggest that similar measurements of small intestinal secretory function in other nonspecific diarrheal diseases using the marker perfusion technique may be rewarding.

Effect of antibiotics on incidence of rat intestinal tumors induced by 1,2-dimethylhydrazine dihydrochloride.

The intestinal microflora has been shown to influence the induction of chemical carcinogens responsible for intestinal tumors in animal models. For further exploration of this issue, male inbred F344 rats were administered a chemical carcinogen, 1,2-dimethylhydrazine dihydrochloride (DMH), for 20 weeks, along with oral antibiotics, either tetracycline or erythromycin, to suppress the intestinal flora. Colon cancer incidence was lower in animals receiving antibiotics; 22% of the erythromycin-treated rats and 20% of the tetracycline-treated rats had colon tumors compared to untreated controls with a 74% tumor incidence (P less than 0.002). Tumors in the small intestine also decreased from an incidence of 48% in the control animals to an incidence of 27 and 7%, respectively, for the erythromycin- and tetracycline-treated rats. These findings suggested that the metabolic activity of the intestinal flora is related to cancer induction by DMH.

Alterations of the intestinal microflora by diet, oral antibiotics, and Lactobacillus: decreased production of free amines from aromatic nitro compounds, azo dyes, and glucuronides.

F344 rats were fed compounds containing a nitro, azo, or amine-glucuronide group-2-nitronaphthalene (CAS: 581-89-5), 2-nitrofluorene (CAS: 607-57-8; 2-nitro-9H-fluorene), 4-phenylazo-2-naphthol (CAS: 6410-10-2; 1-[(4-nitrophenyl)azo]-2-naphthol), and 2-naphthylamine-N-D-glucuronide--and the formation of free amines was measured in the feces. The effects of diet (mean vs. grain), administration of antibiotic, and the feeding of Lactobacillus acidophilus were evaluated. Meat-fed rats given 2-nitronaphthalene had approximately 4 times higher concentration of free amines in their feces as compared to the concentration in grain-fed rats. In a similar experiment with 2-naphthylamine-N-D-glucuronide, the meat-fed animals had approximately 1.5 times more of the free amines and 50% less of the conjugates in their feces. When meat-fed animals were given L. acidophilus with 2-nitrofluorene or 2-naphthylamine-N-D-glucuronide, they had significantly lower free amines and higher concentrations of conjugates in their feces than did the meat-fed controls. Similarly, erythromycin or tetracycline decreased the fecal amine production in meat-fed animals that had received 2-nitrofluorene or 4-phenylazo-2-naphthol. In another experiment, erythromycin inhibited the production of free amines from 2-naphthylamine-N-D-glucuronide in rats fed a high-fat diet. Studies of fecal enzymes revealed lower levels of beta-D-glucuronidase, nitroreductase, and azoreductase in grain-fed rats and in meat-fed animals also given antibiotics or lactobacilli. These experiments showed that intestinal flora have the ability to convert exogenously administered aromatic nitro and azo compounds and an amine-glucuronide compound to free amines. The rate of these conversions was affected by diet and by oral administration of antibiotics and lactobacilli.

The relationship between diet and rat fecal bacterial enzymes implicated in colon cancer.

We studied the effect of diet on the activities of four enzymes found in the intestinal flora of the male F344 rat. Animals initially fed a diet with high vegetable and grain content were shifted to a diet consisting predominantly of beef. While eating the meat diet, the rats had significantly higher levels of nitroreductase, azoreductase, and beta-glucuronidase in their fecal flora when compared to levels measured during grain feeding. However, beta-glucosidase activity was significantly lower during meat feeding, which probably reflected the lack of beta-glucosidic linkages in this diet. These findings suggested that a high-beef diet, similar in composition to that consumed by humans with a relatively high risk of colon cancer, is associated with elevated levels of specific enzymes in the colon microflora. These enzymes have been implicated in the conversion of procarcinogens into carcinogens.

Effect of Lactobacillus acidophilus dietary supplements on 1,2-dimethylhydrazine dihydrochloride-induced intestinal cancer in rats.

The epidemiologic patterns of large bowel cancer have implicated a diet high in beef as a risk factor. Another study has shown less colon cancer in Finns than in Danes. Among the possible explanations were the consumption of milk and fermented dairy products and the numbers of lactobacilli in the fecal flora, both of which were higher in the Finns. As a test of these hypotheses, 20 mg 1,2-dimethylhydrazine dihydrochloride/kg body weight was administered for 20 weeks to male inbred F344 rats. Rats consuming a beef diet simulating a "Western" diet had higher rates of colon cancer than did grain-fed rats (83% vs. 31%, respectively). Viable cultures of Lactobacillus acidophilus were fed to rats eating the meat diet; the rats were then challenged with 1,2-dimethylhydrazine dihydrochloride. The colon cancer incidence after a 20-week induction period was lower in the animals receiving the L. acidophilus (40% vs. 77% in controls), but no difference in incidence was discerned after a 36-week period. Thus dietary supplements of L. acidophilus seemed to increase the latency or induction time for experimental colon cancer.

Dietary fat reduction and plasma estradiol concentration in healthy postmenopausal women. The Women's Health Trial Study Group.

Concentrations of total and weakly bound plasma estradiol were significantly (P less than .01) reduced in 73 healthy post-menopausal women after 10-22 weeks of participation in a low-fat diet intervention program. Nonsignificant reductions in estrone sulfate and sex hormone-binding protein were also observed. The 17% reduction in average estradiol concentration was accompanied by an average reduction of 12 mg/dL in total plasma cholesterol (P less than .001), an average weight loss of 3.4 kg (P less than .001), and an average reduction in daily dietary fat from 68.5 to 29.5 g. Our review of case-control studies indicates that a 17% reduction in plasma estradiol may explain a noteworthy component of the international variation in breast cancer incidence. We find a need for further studies of (a) disease risk in relation to hormone concentrations and (b) changes in hormone concentrations as a function of the duration of low-fat diet intervention.

Effect of diet and Lactobacillus acidophilus supplements on human fecal bacterial enzymes.

The effect of diet and Lactobacillus acidophilus supplements on fecal microflora enzyme activity was studied in humans. The bacterial enzymes that were investigated are known to catalyze reactions that may result in formation of proximal carcinogens. Compared to vegetarians, omnivores eating a "Western-type" diet had higher levels of beta-glucuronidase, nitroreductase, azoreductase, and steroid 7-alpha-dehydroxylase in their fecal microflora. Removal of red meat or addition of fiber in the form of bran or wheat germ to the diet of omnivores for 30 days had no effect on beta-glucuronidase, nitroreductase, or azoreductase activity. However, removal of red meat or addition of fiber reduced fecal steroid 7-alpha-dehydroxylase activity. The addition of viable Lactobacillus acidophilus supplements to the diet of omnivores significantly decreased fecal bacterial beta-glucuronidase and nitroreductase activities. Thirty days after Lactobacillus supplements were curtailed, fecal enzyme levels returned to normal base-line activities. These findings suggested that the metabolic activity of the fecal microflora was influenced by diet and could be altered by Lactobacillus supplements and to a lesser extent by dietary fiber.

Hormone levels during dietary changes in premenopausal African-American women.

BACKGROUND: In the United States, 5-year survival rates of 69% and 84%, respectively, have recently been reported for African-American and Caucasian women diagnosed with breast cancer. Differences in the levels of endogenous sex hormones in these populations could explain some of the variation in survival rates, since estrogen is recognized as a risk factor for this type of cancer. PURPOSE: Dietary factors are known to affect endogenous hormone levels; therefore, our study was designed to determine the serum hormone levels of African-American women consuming a typical North American diet, to determine the effect of a low-fat and high-fiber diet on their serum hormone levels, and to compare the base-line serum hormone levels in the African-American women with hormone data from our study of Caucasian women (n = 68) consuming the same control diet. METHODS: Twenty-one healthy, premenopausal, African-American women who agreed to eat only food prepared in a clinical study unit were recruited into the study. The control diet was similar to their usual diet, being high in fat (40% of calories from fat) and low in fiber (12 g/day), and was consumed on average for 3 weeks. The concentrations of estrone (E1), estrone sulfate (E1SO4), estradiol (E2), free E2, androstenedione, and sex hormone-binding globulin (SHBG) in serum samples obtained from the participants during the last week of the control diet and during the follicular phase of their menstrual cycle were determined. The women were then switched to a diet low in fat (20% of calories as fat) and high in fiber (40 g/day); they consumed this diet for two menstrual cycles before blood samples were collected for determination of serum hormone levels. Repeated-measures regression modeling was used to investigate the relationship between diet and hormone levels in African-American and Caucasian women. All P values resulted from two-sided statistical tests. RESULTS: Analysis of serum hormone levels in the African-American women indicated that the change in diet caused a significant decrease in E2 (-8.5%; 95% confidence interval [CI] = -16.1% to -0.3%; P < or = .03) and E1SO4 (-16.2%; 95% CI = -22.1% to -9.8%; P < .0001) and a significant increase in androstenedione levels (+18.3%; 95% CI = +10.3% to +26.8%; P < .0001). SHBG levels of the African-American women were 5.6% (95% CI = -14.0% to +3.7%) lower for those on the experimental diet compared with those on the control diet, but the difference was not statistically significant. Comparison of control serum hormone values in the African-American women in this study with those in Caucasian women previously studied indicated that the Caucasian women had statistically significant lower levels of E1 (-37%; 95% CI = -61.2% to -16.4%; P < or = .0002), E2 (-54.5%; 95% CI = -90.9% to -25.1%; P < or = .0001), free E2 (-30.2%; 95% CI = -65.7% to -2.3%; P < .03), and androstenedione (-48.3%; 95% CI = -83.7% to -19.7%; P < or = .0004). CONCLUSION: African-American women appear to have higher levels of serum hormones than Caucasian women, and dietary modification can result in a lowering of serum estrogens.

Estrogen metabolism and excretion in Oriental and Caucasian women.

BACKGROUND: Caucasian and Oriental women have different incidence rates of breast cancer. Among the underlying risk factors for the development of breast cancer in the women of these two groups may be their different diets and patterns of estrogen metabolism and excretion. The absolute levels and relative ratios of 16 alpha-hydroxylated estrogens and 2-hydroxylated estrogens (catechol estrogens) in the body may have a role in the etiology of breast cancer, but studies so far have provided only conflicting results. PURPOSE: Our goal was to study estrogen metabolism, in particular, the extent of 2-hydroxylation and 16 alpha-hydroxylation of estrogens in two groups of women, one Caucasian and one Oriental, with inherently different breast cancer risks. METHODS: Dietary records were analyzed over 3-day periods in the mid-follicular phase, twice, at 6-month intervals for 13 premenopausal Oriental women, recent immigrant arrivals in Hawaii with presumed low risk of breast cancer, and for 12 premenopausal Finnish women with presumed higher risk. The urinary estrogen profile was measured by gas chromatography-mass spectrometry and plasma and fecal estrogens were assayed by chromatographic radioimmunoassays. RESULTS: Mean fat intake per 1000 kcal was 73% higher (P < .001) in the Finnish women, but the mean fiber intake and fecal weights were similar to those of the Oriental women. Compared with Oriental women, Finnish women had 46% higher plasma estradiol (P < .01) and 124% higher plasma estrone sulfate (P < .01); however, after adjustment for differences in age and body mass index, only the difference in estrone sulfate remained statistically significant (P < .05). Mean plasma levels of estrone and estradiol correlated with height after adjustment for body mass index (P < .05). Mean plasma levels of estrone and sex hormone-binding globulin were similar. The Finns had higher mean urinary estrone (193%), estradiol (166%), various catechol estrogens (130%-439%), and total estrogen excretion (123%) (all P < .001), but similar 16 alpha-hydroxylated estrogen excretion. As calculated, 16 alpha-hydroxylation of estrone was significantly increased (P < .01) in the Oriental women, but 2-hydroxylation, 4-hydroxylation, and 16 beta-hydroxylation of estrone were similar in both groups. The ratio of catechol estrogen to 16 alpha-hydroxylated estrogen was four to five times higher (P < .001) in the Finnish women. The Oriental women had two to three times higher fecal excretion of estrogens than the Finnish women (P < .01). CONCLUSIONS: Our results indicate that high catechol estrogen formation may be a greater risk factor for breast cancer than high 16 alpha-hydroxylation of estrogens. However, the main risk factor for the Finnish women, as opposed to the Oriental women, may be their higher estrogen levels that result from a higher fat diet, higher estrogen production related to their greater height, and lower fecal estrogen excretion.

Effect of diet on excretion of estrogens in pre- and postmenopausal women.

Fecal, urinary, and plasma estrogens and plasma androgens were studied in healthy pre- and postmenopausal vegetarian and omnivorous women. Dietary histories of the subjects revealed that omnivores consumed a higher percentage of total protein and fat from animal sources. The total 72-hr fecal excretion as measured by dry weight was higher for vegetarians. Preliminary results indicate that vegetarian women excrete 2 to 3 times more estrogens in feces than do omnivores and that omnivores have about 50% higher mean plasma level of unconjugated estrone and estradiol than vegetarians. Estriol-3-glucuronide, a compound that is formed upon reabsorption of free estriol from the intestine, is found in lower concentrations in the urine of vegetarians. These data suggest that in vegetarians a greater amount of the biliary estrogens escape reabsorption and are excreted with the feces. The differences in estrogen metabolism may explain the lower incidence of breast cancer in vegetarian women.

Enzymatic methylation of microsomal metabolites of benzo(a)pyrene.

These studies suggest that the microsomal metabolism of benzo(a)pyrene (BP) produces metabolites which can be methylated by the catechol-o-methyltransferase (COMT)/S-adenosylmethionine (SAM) enzyme/donor combination. Induced microsomes converted 12 to 15% of substrate BP to polar products. Approximately 0.06% of substrate BP was recovered as COMT/SAM-reactive substances. In tests for specificity, COMT/SAM was found to react with catechols, but not with dihydrodiols, quinones, a phenol, an epoxide, or 1,4-hydroquinone. Organic extracts of COMT/[14C]SAM incubations with BP were fractionated by high-performance liquid chromatography. The appearance of radiolabeled chromatographic bands required the presence of substrate BP, microsomes, and COMT/[14C]SAM. When the Ames mutagenesis assay was supplemented with COMT/SAM, a 36% reduction was observed in the number of revertant colonies induced by the microsomal oxidation of BP. In contrast, the mutagenic properties of 2-aminofluorene were not affected by COMT/SAM. These observations indicate that COMT/SAM does not generally inhibit mixed-function oxidase activity but rather reacts with substances which are activated by ring oxygenations.

Prostatic abscesses involving anaerobic bacteria.

Anaerobic bacteria have seldom been reported in prostatic abscesses. The present study concerns four cases in which the exudate was cultured with optimal microbiological techniques. Our results showed a complex aerobic-anaerobic flora in each instance, with a total of 21 isolates, including seven aerobes and 14 anaerobes. This experience has important implications concerning culture practices and empiric antimicrobial treatment for patients with prostatic abscess.

Bacteriology of hospital-acquired pneumonia.

Hospital-acquired pneumonia was studied prospectively for 3 1/2 years in a 549-bed facility with acute medical-surgical care wards, convalescent wards, and a chronic care unit. Bacteriological studies were limited to transtracheal aspirates, pleural fluid, and blood cultures. The predominant isolates in 159 patients were gram-negative bacilli (47%), anaerobic bacteria (35%), Staphylococcus aureus (31%), and Streptococcus pneumoniae (26%). Nearly half of all specimens yielded a polymicrobial flora with more than one potential pathogen. Distribution of pathogens was similar with analysis of all patients, including patients with a monomicrobial infection and patients with bacteremic pneumonia. The prevalence of cases and distribution of bacteria were similar for patients located on acute medical-surgical wards and those in the nursing home care unit. Nosocomial pneumonia was judged directly responsible for lethal outcome in 19% of patients and a contributing factor to death in another 13%.

Results of a randomized feasibility study of a low-fat diet.

A 2-year randomized clinical trial was conducted to test whether free-living women aged 45 to 69 years can reduce the fat content of their diet from the typical US level of approximately 39% to 20% of energy from fat, using readily available foods, when given nutritional and behavioral counseling and social support. Three clinical units randomized 303 selected volunteers into intervention (low-fat eating plan) or control (customary diet) groups. The two groups were comparable at baseline. The intervention group received nutrition instruction and behavioral counseling largely in permanent groups of 12 to 15 participants meeting weekly, then biweekly, and finally monthly. At 6 months, they had substantially reduced the mean proportion of total energy from fat from 39.1% to 20.9%, compared with the control group's nonsignificant reduction from 39.0% to 38.1%. At 12 and 24 months, they sustained the reduction of energy from fat. Weight loss and plasma cholesterol level changes in the intervention group supported the self-recorded dietary intake changes. Attendance at intervention sessions averaged 75% during the first 6 months and, subsequently, 60% to 70%. Four-day food records for the randomized women were obtained at 6 and 12 months from approximately 95% and at 24 months from 87%. A clinical trial of a low-fat diet is feasible in women.

Short-term progressive resistance training increases strength and lean body mass in adults infected with human immunodeficiency virus.

BACKGROUND: To assess the efficacy of progressive resistance training (PRT) in increasing strength and lean body mass (LBM) in HIV-infected adults. METHODS: Twenty-five adults with HIV infection were trained using a highly intensive PRT regimen for 8 weeks, followed by an additional 8 weeks of observation under ad libitum physical activity conditions. RESULTS: Twenty-four of the 25 patients completed the first phase of the study. They had significant increases in strength on all four exercises tested (P < 0.0001), and an increase in LBM of 1.75 +/- 1.94 kg (mean +/- SD, P < 0.0002), with a concomitant decline in fat of 0.92 +/- 2.22 kg (P < 0.05), and no significant change in weight or bone mineral content. Twenty-one of the patients returned for follow-up 8 weeks after completing the PRT. Compared with their baseline values, their mean lean mass remained 1.40 +/- 1.8 kg higher (P < 0.003). Among those who continued to train to some extent, lean mass increased by a mean of 1.1 +/- 1.6 kg (n = 9, P < 0.05 versus end of PRT), whereas those who did no further training showed an increase in lean mass of 0.28 +/- 1.4 kg (n = 12, P = NS versus end of PRT). The difference between the two groups was not, however, significant (P = 0.25). Among six patients with AIDS wasting, the increase in LBM was larger than among non-wasted patients (2.8 versus 1.4 kg, P < 0.06), and there was an increase in both weight (+3.9 versus -0.2 kg, P < 0.002) and fat mass (+ 0.95 versus -1.5 kg, P < 0.002) at 8 weeks, which persisted at 16 weeks (weight: +4.0 versus -1.6 kg, P < 0.0002; fat: +1.6 versus -1.9 kg, P < 0.01). CONCLUSION: This preliminary study suggests that short-term, high intensity PRT can significantly increase LBM and strength in HIV infection, and may be used as an alternative or adjunct to pharmacological anabolic treatments in this disease.